Bilge pump

ABSTRACT

1,175,776. Electric motors; carrying conductors into casings. CROWELL DESIGNS Inc. 22 April, 1968 [23 May, 1967], No. 18859/68. Headings H2A and H2E. [Also in Division F1] In a submersible pump (see Division F1), an electric driving motor 12 in the upper portion of an air-bell 10, is supported via a resilient ring 39 by a partition wall 37. The portions 46 of the motor supply leads are stripped of their conventional insulation 47 and are sealed to the wall of the air-bell by a plastics material, e.g. an epoxy material 60.

Nov. 5, 1968 w. R. DAVENPORT ET BILGE PUMP 2 Sheets-Sheet 1 Filed May23, 1967 INVENTORS: W/ZZ/AM 9 DAVf/VFJAZ' EAMER 7 DAVENPORT ATTORNEY$NOV. 5, 1968 w R DAVENPORT ET AL 3,408,942

BILGE PUMP 2 Sheets-Sheet 2 Filed May 23, 1967 INVENTORS W/LL/A/W P.DAVE/V1 01??- ELMi/E 7- @flVfA/Paef BY. f

ATTORNEYS United States Patent Office Patented Nov. 5, 1968 3,408,942BILGE PUMP William R. Davenport, Bricktown, and Elmer T. Davenport,Point Pleasant, N.J., assignors to Crowell Designs Inc., a corporationof New Jersey Filed May 23, 1967, Ser. No. 640,597 8 Claims. (Cl.103--87) ABSTRACT OF THE DISCLOSURE An air-tight bell-shaped housingaccommodates a motor in its closed upper portion, an impeller beingmounted on the lower end of the motor shaft. A pump body within openlower end of housing, but unconnected thereto, defines impeller chamber.A pump cover, seated on pump body, is fixed to housing by wallsextending upwardly from cover. Walls have holes for escape of liquidaccumulating above the cover.

Plate fixed to housing below motor supports motor and mechanically sealsit, in liquid-tight fashion, from lower part of housing.

This invention relates to pumps, and more particularly to pumps, such asbilge pumps, intended to remove water or other liquid from the bilge ofa boat or the sump of a basement. 7

Such pumps, when in use, are partially or completely submerged in theliquid being pumped. Consequently, in the past, some pumps of this typehave been provided with air-tight bell-shaped housings capable oftrapping air within them. As the water level in the bilge rises, thepressure of the trapped air increases, whereby the air limits the levelto which the water within the housing is permitted to rise. In this way,the pump motor mounted within the upper portion of the housing is keptout of contact with the water.

Known pumps of this type present certain problems in connection withmaintenance and reliability which are overcome by the present invention.

It is an object of this invention to provide a bilge pump wherein thepump motor is separated from the liquid-engaging portion of the pump byboth a trapped air volume and a mechanical liquid-tight barrier. As aresult, should all or a major portion of the trapped air escape, such asby the pump accidentally overturning, the motor will be kept dry by themechanical sealing means.

It is another object of the invention to provide such a pump wherein thepump housing may be readily lifted away from the pump body, i.e., theportion defining the impeller cavity, without disturbing the mounting ofthe pump body, so as to expose the impeller for repair or replacement,and expose the cavity for cleaning.

It is a further object of the invention to provide such a pump whereinthe bushing which supports the impellercarrying motor shaft as it passesthrough the pump cover is constantly lubricated by the liquid beingpumped even after all the liquid in the bilge has been removed.

To achieve these objectives, the invention provides an air-tight,bell-shaped housing accommodating a motor in its upper closed portion,the motor shaft extending downwardly toward the open lower end of thehousing. An impeller is carried by the lower end of the motor shaft, anda pump body, defining a cavity for the impeller, is located within theopen lower end of the housing. The pump body is adapted to be secured tothe support surface for the pump, but is unconnected to the housing. Thebottom wall of a cup-shaped pump cover unit seats upon the pump body toclose the impeller cavity, and the walls of the pump cover unit aresecured to the housing. Thus, the housing and the pump cover unitattached to it can simply be lifted away from the pump body to exposethe impeller and impeller cavity.

A bushing preferably surrounds the portion of the motor shaft passingthrough the pump cover, and a small volume of the liquid being pumpedsqueezes upwardly between the bushing and shaft to lubricate them. Theliquid partially fills the cup-shaped cover unit, and escapes back tothe bilge through holes in the cup walls. A small amount of liquidremains in the cup after pumping has been completed and serves tocontinue lubricating the shaft and bushing should the pump continue torun. Of course, if the pump cover is made of suitable material, and thehole in the pump cover through which the motor shaft passes is so sizedthat the shaft fits snugly within the hole, the bushing could beeliminated.

A support plate for the motor is secured to the housing below the motorand above the pump cover. The plate incorporates mechanical,liquid-tight seals, including a seal surrounding the portion of themotor shaft passing through the support plate. The plate, therefore,forms a liquid-tight barrier between the motor compartment of thehousing and the remainder of the pump. During normal operation, liquidat the outlet pressure of the pump does not contact the mechanicalseals, nor does any liquid whatsoever. Therefore, the mechanical sealshave a long life, and are ready at any time to serve their back-upfunction of keeping liquid away from the motor should the trapped airwithin the housing escape.

A feature of the invention is the manner in which the electricalconductors feeding the motor pass through the housing so as not todestroy its air-tight character. It has been found that when insulatedwires extend through a hole in the housing, and the hole is plugged, aircould nevertheless escape by flowing between each wire and itsinsulation. Consequently, in the present pump, the portion of the wirespassing through the hole in the housing are stripped of insulation, andthe hole is then plugged with a suitable material, such as an epoxy.

Other features and advantages of the invention will be apparent from thefollowing description in which reference is made to the accompanyingdrawings.

In the drawings:

FIG. 1 is an elevational view of a pump according to this inventionlooking into the pump outlet;

FIG. 2 is a vertical cross-sectional view taken on line 2-2 of FIG. 1;

FIG. 3 is a horizontal cross-sectional view taken on line 33 of FIG. 2;and

FIG. 4 is a horizontal cross-sectional view taken on line 4-4 of FIG. 2.

-In the description which follows, and sometimes hereinabove, the pumpis referred to as a bilge pump, the region from which liquid is removedis referred to as the bilge, and the liquid being pumped is referred toas water. However, it is to be understood that the environment in whichthe pump may be used is not limited to boats, and liquid moved by thepump may be other than water.

The pump chosen to illustrate this invention includes a bell-shapedhousing 10, the top and side walls of which form an air-tight enclosure,but the bottom of the housing being open. The lower end of the housingside wall is formed with attachment feet 11 (FIGS. 1 and 4) projectingradially outwardly, by means of which the housing may be secured to thesupport surface for the pump, such as the bilge floor. Accommodatedwithin the upper region of the housing is an electric motor 12, havingan output shaft 13 projecting downwardly toward the open lower end ofthe housing. A pump impeller 14 is secured to the lower end of the motorshaft 13 by means of a screw 15.

Arranged within the lower, open end of the housing 1t) is apump body 16having a bottom wal1 17 and side walls 18. The pump body defines animpeller cavity within which the impeller 14 is located. The bottom wall17 is provided with an inlet opening 21 though which water enters thecavity, and the side walls 18 are formed with a tangentially arrangedoutlet nipple 22 through which the pumped water leaves the cavity. Ahose 23 may be attached to the nipple 22. The pump body 16 has legs 24which space the bottom wail 17 above the bilge floor, and by means ofwhich the pump body may be fastened to the bilge floor, such as by meansof screws 25. Projecting upwardly from each leg 24 is a clip 26 havingan outwardly facing, rounded protrusion adapted to snap into a detent inthe inner surface of the housing side wall. The clips 26 help toposition the housing with respect to the body 16, but do not connect thetwo since the housing can readily be lifted off the pump body, in whichcase the clips slip out of engagement with the detents in the housing.

The lower ends of the housing side walls are provided with an enlargedslot 27 capable of passing over the nipple 22, and a series of smallerslots 28 through which Water flows from the bilge to the pump inlet 21.

Seated upon the upper edge of the walls 18 is a cup-shaped pump coverunit, the bottom wall 31 of which serves as the top wall of the impellercavity. An O-ring 32 forms a water-tight seal between the walls 31 and18. The walls 33 of the cup-shaped unit extend upwardly, and terminateat their upper ends in an outwardly projecting flange 34 by means ofwhich the unit is secured to the housing 10, as by screws 35. The walls33 are provided with a pair of openings 36, the lower edge of eachopening being spaced above the bottom wall 31 of the cup.

Also secured to the housing 10 by the srews 35 is a support plate 37 forthe motor 12. The upper face of the support plate has an annular grooveaccommodating an O-ring 38 which forms a water-tight seal between theplate 37 and housing 10. The motor does not rest directly upon the plate37, but instead rests against an O-ring 39 wedged between the motor,housing, and plate. The O-ring 39 does not serve as a seal but rather asa resilient shock absorber. The motor shaft 13 extends downwardlythrough a central hole in the plate 37 surrounded by a boss 42.Supported within the boss 42 is a suitable seal 43 which permitsrotation of the shaft 13 with respect to it, but which produces awater-tight seal against the shaft.

The motor shaft 13 also extends through a central hole in the pump coverbottom wall 31, the hole being lined by a suitable bushing 44 whichabsorbs the reaction force on the impeller of the water leaving thepump. The bushing fits snugly around the shaft 13 and thereby limitsgreatly the amount of water which has a tendency to creep up the shaft13 as the latter rotates. Nevertheless, the fit of the bushing aroundthe shaft is loose enough to permit a small volume of water to flowbetween them.

The top wall of the housing 10 is provided with a hole surrounded by alow wall 45. The portions 46 of the electrical conductors, supplyingcurrent to the motor 12, which pass through the hole in the housing arestripped of insulation 47, and the hole and cavity defined by the wall45 are filled with a suitable plastic, such as an epoxy material. Sincethe plastic comes into intimate contact with both the housing 10 and theuncovered wires 46, the air-tight character of the housing 10 ispreserved.

When the pump is in operation, the impeller 14 is rotated by the motorshaft 13, and water from the bilge enters the inlet 21 and is pumped outof the outlet 22 and hose 23. Due to the presence of the plate 48 at theupper ends of the impeller blades, pump outlet pressure is present atthe lower end of the bushing 44. Therefore, water seeps upwardly betweenthe bushing 44 and shaft 13 thereby lubricating these parts. As thewater accumulates in the cup, above the wall 31, it reaches the level ofthe openings 36, and flows back into the bilge. Consequently, it will beappreciated that, in normal operation, water never reaches themechanical seal 43. Hence, this seal stays dry and free of dirt and gritoften carried by the bilge water. Once the bilge is dry, the pump may beturned off. However, if throughin advertence the pump is left running,the water remaining above the wall 31 will slowly seep down between'theshaft 13 and bushing 44 to keep these parts lubricated.

Should access to the impeller become necessary, the housing 10 is simplylifted upwardly, and of course the motor 12, shaft 13, impeller 14,plate 37 and pump cover unit 31, are raised as a unit with the housing;The pump body 16, on the other hand, remains fastened to the bilgefloor. Since the cover 31 ofthe impeller cavity has been lifted, thecavity is open to view. Furthermore, the impeller 14 is exposed on thelower face of the wall 31.

If during the operation of the pump, the housing should accidentallybecome overturned, thereby allowing all the trapped air to escape, noinjury can come to the motor 12 due to the mechanical water-tightbarrier comprising the plate 37 and seals 38 and 43.

The invention has been shown and described in preferred form only, andby way of example, and many variations may be made in the inventionwhich will still be comprised within its spirit. It is understood,therefore, that the invention is not limited to any specific form orembodiment except insofar as such limitations are included in theappended claims.

What is claimed is:

1. A pump comprising:

(a) a housing having side walls and a top wall forming an air-tightenclosure, the lower ends of said side walls defining an opening intosaid housing. 7

(b) a motor supported within the upper portion of said housing, theoutput shaft of said motor extending downwardly toward said opening,

(c) an impeller secured to the lower end of the motor shaft,

(d) a pump body adapted to be secured to a support surface for the pump,said body being within said housing opening but unconnected to saidhousing, and said body having bottom and side walls defining an impellercavity, inlet and outlet openings for said cavity formed in said pumpbody,

(e) a pump cover seated upon the upper edges of said pump body sidewalls in fluid tight relation and forming the top wall of the impellercavity, the motor shaft passing through a hole in said cover, and

(f) means for affixing said cover to said housing, whereby said housingand pump cover may be lifted as a unit away from said pump body toexpose said impeller and impeller cavity for cleaning and repair.

2. A pump as defined in claim 1 including a bushing lining the hole insaid pump cover, said bushing fitting snugly around the motor shaft butpermitting a low volume portion of the liquid being pumped to passupwardly between the shaft and bushing when the pump is pumping theliquid, whereby said bushing is lubricated by the liquid.

3. A pump as defined in claim 1 wherein said afiixing means (f) includesa wall secured to said pump cover and projecting upwardly therefrom, andfasteners securing said wall to said housing.

4. A pump as defined in claim 3 wherein said pump cover and pump coverwall are integrally formed as a cup-shaped member.

5. A pump as defined in claim 4 including an opening in said pump coverwall through which liquid which flows upwardly through the hole in saidpump cover may escape from said cup-shaped member.

6. A pump as defined in claim 5 including a bushing lining the hole insaid pump cover, said bushing fitting snugly around the motor shaft butpermitting a low volume portion of the liquid bein pumped to passupwardly between the shaft and bushing and into said cupshaped member,and wherein said opening in said pump cover wall is spaced above saidpump cover so that a volume of the liquid remains in said cup-shapedmember even after the region in which the pump is located is dry wherebysaid remaining liquid serves to lubricate said bushing should the pumpcontinue to run.

7. A pump as defined in claim 1 including a motor support plate securedto said housing in liquid-tight relation below the motor body and abovesaid pump cover, a hole in said plate accommodating the "motor shafit,and a liquid-tight seal within said support plate hole and engaging saidshaft.

in said housin through which electrical conductors extend to said motor,the portions of said conductors passing through said hole being free ofinsulation, and a mass of plastic plugging said hole and surrounding 5said conductors in air-tight relation.

References Cited UNITED STATES PATENTS 10 2,320,708 6/1943 Yost 103-872,381,834 8/1945 Mcredew et a1 103-87 3,256,828 6/1966 Rule 10387 ROBERTM. WALKER, Primary Examiner.

8. A pump as defined in claim 1 including a hole 5

